How was it done?

The refined syntax trees were then transformed into
conceptual graphs using rules based on the grammars produced in step 1. The rules
were used for word-level and phrase-level up to just below
clause-level. At clause-level, a different algorithm took over.

The result was CGs which
were "pretty good" but still not satisfactory.

Finally, the CG output of step 2 was refined into
fully semantic CGs with no syntax left, using rules which transformed subgraphs into more
semantically adequate subgraphs.

The final graphs was CGs which
were now "rather good", being fully semantic with no syntax
left.